Pneumatic tire pressure indicator system



March 15, 1932. H. A. DENMIRE PNEUIA TIG TIRE PRESSURE INDICATOR SYSTEM 7 Filed Oct. 2, 1926 InUEn uz' Harold A Demmre w E. X L W |l|ll|||l|l 2. B I m. 0 M Y 1 I V 3 J 5 8 5 3 m 4L 4 I. 7 I O WWW a 1 6.

March 15, 1932. DENWRE 1,849,139

PNEUMATIC TIRE PRESSURE INDICATOR SYSTEM Filed Oct. 2, 192% s Sheets-Sheet 2 I r 1 I r 1 1 1 1 I I l I I x 77a. 77 ,1

In UEnIm".

Harold R. benmi re ammazv ve AW g5.

March 15, 1932. A, DENWRE 1,849,139 PNEUMATIC TIRE PRESSURE INDICATOR SYSTEM Filed Oct. 2/1926 3 Sheets-Sheet 5 1 g j 35: 3g. [TIL/E127 01-" 39 *5 j Hamid A.Denmire reamed Mar. 15, 1932 UNITED sa HAROLD A. DENMIRE, OF AKRON, OHIO, AS SIGNUR T THE GENERAL TIRE Q3 liEtlZl'IBSIBEZR.v

' COMPANY, 03 AKRON, GHIO, A CORIPQBATION OF OHIG I PNEUMATIC TIRE IPBEQSURE INDICATQR SYSTEK Application filed Gctober 2, 1926. Serial No. 139,055.

I. This invention relates to pressure indicating systems and particularly to means for indicating the pressures in pneumatic t res of a vehicle during operation of the vehicle 5 and the like.

One of the objects of the invention is to provide a pressure indicating mechanism that will transmit fluid pressure indications from a moving part to a stationary part of a machine.

Another object of the invention is to provide a reliable and reasonably accurate pneumatic tire pressure indicator that may be carried on the instrument board of a vehicle arid that will indicate the inflation pressures of different vehicle tires during operation of the vehicle.

An additional object of the invention is to maintain the same inflation pressure in a pair of dual-mounted pneumatic tires when the inflation pressure of the tires is above a predetermined desired safe operating pressure and to cut ofl communication between the tires if the pressure drops below a desired 2 minimum operating pressure.

Another object of the invention is to provide a single indicator that will satisfactorily indicate the inflation pressures in a. pair of dual-mounted tires.

Another object of the invention is to provide a hydrostatic pressure indicating mechanism that will be substantially free from errors due to variations in the operating temperature of the device.

Pneumatic tire indicators adapted for mounting on the dash of a vehicle have heretofore been proposed. Applicants invention (litters from previously proposed methods of remotely indicating the pressure of the tires, '40 or other relatively rotating bodies, by providing a transmission of the inflation pressures to the indicating device without substantial movement of the communicating parts rather than transmitting the pressure indications by the proportionate movement of parts of the device. In prior structures with which. applicant is familiar, such for instance as structures that depend upon the relative movement of the parts for indications, unsatisfactory operation results from temperature variations and errors in mechanical connections of the indicator parts.

Particular adaptations of the invention to single and to dual-mounted pneumatic tires are shown in the accompanying drawings wherein:

Fig. 1 is a vertical sectional view of one I of the steering wheels of an automotive ve' hicle showing a preferred application of the invention.

Fig. 2 is a vertical sectional view taken substantially through the axis of the vehicle wheel, showing an application of the invention to dual-mounted tires to separately indicate the pressure in each of the tires.

Fig. 3 is a vertical sectional view, taken substantially through the axis of a vehicle Wheel, showing one indicator used to indicate the pressure in communicating dual-mounted tires.

Fig. 4 is an enlarged vertical sectional view of a valve device that is adapted to maintain open pressure communication between the pair of dual-mounted tires shown in Fig. 3 when the pressure is above a predetermined value and that cuts off communication between the tires when the pressure of either tire drops below a predetermined safe operating value.

Fig. 5 is an enlarged face view, with parts broken away, of one of the races of a thrust bearing used in connection with the inven tion.

Fig. 1 shows an application of the invention to a single vehicle tire carried on one of the front steering wheels 1 of an automotive vehicle. In this installation, a pressure tube 2 that is in open communication with'a vehicle tire carried on the wheel 1, serves to maintain a pressure the same as the tire inflating pressure within the pressure ring 3 that is carried by the wheel 1.

The circumferential folds 4 of the pressure ring 8 provide a bellows-like fold in the ring that permits its lateral extension in an axial a5 direction with very little frictional resistance and also with little resistance from tension in the walls of the pressure ring.

The distcnsible pressure ring 8, which is preferably made of rubber or rubber and 10a fabric with circumferential folds 4 extendmg around its inner and outer circumference, 15 carried in an annular groove that 18 formed between the concentric side walls of a suit-- 5 able housing member 5 that is secured in place on the vehicle wheel 1 by the bolts 6 that extend through suitable apertures formed in a flange 7 that is formed on the housing.

The pressure ring 3 acts directly upon one race" 8 of a thrust bearing to transmit pressures through the thrust bearing to a second pressure ring 9 that is filled with liquid. The I chine screws 12. The thrust bearing race 13' that opposes the race 8 through a series of ball bearings 14, is also slidably carried in the bracket 10. The bearing race 13 and pres sure tube 9 against which it acts are relatively stationary whereas the pressure ring 3 and 3 bearing race 8 turn with the wheel 1. The ball bearings 14 serve to transmit the lateral thrust from the air inflated pressure ring 3 to the liquid filled pressure ring 9. The race members 8 and 13 may be of fibre, metal or other material since. the imposed pressure will not be great. If fibre is used, lubrication will be unnecessary. If metal is used it may be desirable to lubricate the parts with some lubricant that is not harmful to rubber or such other material as the pressure rings 3 and 9 are made from.

The liquid filled pressure ring 9 communicates with an indicating instrument 15 of any suitable character, through a flexible liquid filled tube 16 that exten wheel to any suitable mounting place for the indicator 15.

The operation of this device will be readily understood. The thrust that is imposed on the moving bearing race 8 by the air inflated pressure ring 3 is irectly proportional to the inflating pressure of the tire with which the pressure ring communicates at all times through the tube 2. The thrust bearing in turn transmits this pressure to the liquid filled pressure ring 9 which communicates directly with the indicator 15 through tubular connection 16. The indicator dial is calibrated to show tire pressures directly thereon.

The liquid filled pressure ring 9 and indicator connections are responsive to minute movement of the bearing race 13 because of the incompressible nature of the liquid contained therein. On the other hand the air s from the vehicle filled pressure ring 3 is readily extensible and it will cause the bearing race 8 to follow up any relative lateral movement of the bearing race 13 to maintain the same pressure on the bearing race 13 regardless of movements th-erein'that may be caused by loose mechanical parts or by temperature changes in the volume of liquid in the system. For these reasons the indications of the instrument will be substantially free from temperature vari ations and loose mechanical connections.

The application of the invention to dually mounted tires in which separate indication is" desired for each tire is shown in Fig. 2.

This structure comprises a pair of pneumatie vehicle tires 17 and 17a that are respectively connected to an independent pair of concentrically mounted pressure rings 18 and 19 through tubes 20 that enter the respective valve stems of the tires to provide a permanently open connection between the re .spective tires and the corresponding pressure ring.

The pressure rings 18 and 19 are carried in suitable concentric spaced annular grooves that are formed iuthe side wall of the body of the wheel hub. The side Walls of the annular grooves or recesses are sufiiciently wide to support the thrust bearing race members 21 an 22 that oppose corresponding race members 23 and 24tof opposite thrust and that are interposed between the air filled pressure rings 18 andl19 and the liquid filled pressure rings 25 and 6 respectively, carried by the stationary vehic e housin 27 An indicator 28 is connected td the liquid filled pres sure ring 25 and an indicator 29 is connected to the pressure ring 26 to indicate the inflation pressure of each tire.

Although the annular grooves in which the pressure rings are mounted are formed respectively in the housing and wheel hub in this device, it will be apparent that they could also be formed in se arate mountings. The operation of each 0 the indicators 28 and 29 is the same as the operation of the previously described indicator. The concentric mounting of the sets of pressure rings and thrust bearing units renders it convenient to mount as many separate indicators on an individual wheel, or other moving part, as is desired. The fluid connections 30 to the pressure rings are also simplified by carrying the connections from the tube in an axial direc tion.

Fig. 3, Fig. 4 and Fig. 5 show an application of the invention to dual-mounted tires that are connected for the transmission of inflating pressure from each to the other in order to maintain uniform inflation in both 1 fjff aeconse 37 was with tire 32 through the at. a...

A valve head 39, that is actuated'by a presf tire 32 and also to the pressure ring.

45 of the indicator mechanism. This is substantially the same as the indicator mechanism described "in connection with j Fig. 1 except that it is mounted on a 15 rear vehicle wheel instead of a front steering wheel. The pressure indicator 46 1s mounted on any convenient part of the ve- II hicleand adapted to indicate both tire pressu-res so long as the valve 33 remains open and to indicate the pressure of tire 32 in the event that the valve head 39 closes the port 41 to thereby cut off communication between the two tires.

As previously set forth, the operation of the pressure regulator valve 33 is manually adjustable to insure cutting off communication between the tires at any desired minimum pressure. It is desired that this pressure" be a safe operating pressure for the tire in order that if one tire is punctured, the other tire may serve to support the vehicle until a re air station is reached. The indication on t e instrument dial of the minimum pressure indicates that the tires require immediate attention.

If a puncture occurs in tire 32 during operation the leakage of pressure from this tire will reduce the inflatin pressure to a point where the spring 42 wi l overcome the pressure of the diaphragm 40 and close communication between the tires. Additional leakage of pressure from tire 32 will then be indicated on the gauge 46 although tire 31 is cut oil? from communication with tire 32 and maintained at a safe operating inflation. On the other hand, if a uncture occurs in tire 31, the reduction 0 pressure on diaphragm 40 will cut off communication between the tires at the minimum permissible operating pressure for the dual tire. The instrument indication will then be substantially constant at the safe minimum operating value although one tire is deflated. The indication of a minimum permissible pres sure on the gauge will at once tell the operator that the outside tire is probably punctured and attention can immediately be given to it. It will be noted, however, that the device prevents the deflation of both tires on one wheel. when a puncture is received in one of them, although communication between the two tires is maintained when the pressure in the two tires exceeds the minimum safe operating value.

It will also be apparent that the two tires 31 and 32-c'an both be inflated from the same outside valve 36 because the inflation pressure-will maintain the communication valve 33 0 en. between them.

other illustrated indicators could be of the recording type and adapted to provide a permanent record of theinflation pressures at which the tires of the vehicle are operated.

operation of tires in taxi service and. the like where tires are often irreparably damaged by operation at under inflation. The knowledge that permanent recordwas being kept I desired, the instrument 46 or of the This would be very useful in checking the i of the operating pressure of the tires would 89 insure careful attention on the partof the operators and also would insure more informatlve service tests of tires."

It will be obvious from a consideration of i the invention as herein described that various .85

modifications can be made in the application of the invention to different mechanisms without departing from the spirit thereof.

It will also be apparent that the invention is adapted for use inthe transmission of one 90 or more independent pressure indications from any rotating body to its associated rel-' atively stationary body.

What I claim is I 1. A pressure system for an automotive vehicle equipped with pneumatic' tires comprising a pair of opposed thrust bearing raceways, one of which is carried by and rotatable with the vehicle wheel, an elongated hollow pressure operated member that is c'onnected with the pneumatic tire mounted on said Wheel and adapted to transmit pressure to said raceway, a second hollow pressure 0perated hydrostatic member carried by the axle for said wheel and having a raceway adapted to oppose the raceway carried by the wheel and to establish communication therebetween that is responsive to pressure within said tire, and a pressure indicator controlled from said raceway carried by the wheel.

2. The combination with an automotive vehicle having pneumatic tires thereon, of an inflation pressure indicating device associated with one of said tires comprising an elonated laterally extensible hollow member subected to the fluid pressure in one of said tires, a thrust bearing race adapted to receive the lateral pressure from said extensible member, said bearing race and said extensible member being carried. by said wheel, a second bearing race opposing the first race and adapted to receive thrustpressures therefrom, a hollow liquid. filled pressure responsive member connected with the second race and adapted to transmit pressures therefrom to a suitable pressure indicating instrument,anda pressureindicatinginstrument connected with said liquid filled pressure responsive member.

3. The combination with an automotive inflation pressure indicating device comprising an extensible hollow inflatable member carried by one of the wheels of the vehicle in open communication with one of said tires, :1 second hollow liquid filled extensible member harried by the support for said wheeha thrust bearing interposed between the exten sible member carried by the support for said wheel and the extensible member carried by said wheel, a pressure indicating instrument,

and a tube connected between the extensible member carried by the support for said wheel and the indicating instrument, the extensible ond hollow extensible member carried by the support and filled with liquid acted upon by q Lseeuse 0nd hollow liquid filled extensible rin carmed by the support for the wheel, a rust bearing interposed between the extensible .mernbers to transmit pressure therebetween,

and a pressure operated indicator connected with the second extensible ring and acted upon by liquid pressures therein.

Intestimony whereof I aflix my signature. 4 HAROLD A. DENMIRE.

the thrust bearing, and pressure indicating means connected with the second extensible device and acted upon by liquid pressures therein.

A pressure indicating device for use in transmitting pressure indications from a rotating body to a support for the rotating body comprising an extensible hollow annular member carried by the rotated body and subjected to the fluid pressure to be indicated, a second h ollow annular extensible member can ried by the support and filled with liquid, a pressure indicating instrument in open communication with the liquid filled extensible chamber and acted upon by liquid pressures therein, a thrust bearing interposed between said extensible members adapted to transmit thrust from the first extensible member to the second extensible member that is substantially proportionate to the fluid pressure to be indicated, each extensible member being of substantially the same diameter and ar ranged concentrically of the axis of rotation of said rotating body.

6. The combination with an automotive vehicle having a pair of dual-mounted pneumatic tires carried on one wheel thereof, of a ported valve mechanism having one port communicating with one of the tires and a second port communicating with the other tire, a diaphragm subjected to the pressure of one tire, and a valve actuated by said diaphragm to cut off communication. between said ports when the pressure in one of said tires decreases to a predetermined minimum value, and a pressure indicating system for use therewith comprising an extensible hollow ring carried by the wheel and in open communication with one of the tires, a sec- 

